In the oil, gas, petroleum, and power industries, various conditions can occur that necessitate immediate shutdown or tripping of the operations, processes or the entire plant. In those industries, a majority of the final control elements of the shutdown systems are implemented by using fast-acting shutdown valves. In such industries, a majority of the shutdown valves can remain open while the process is in a safe and controlled state. However, such valves should be closed or shutdown in situations where the plant experiences a trip arising from an out-of-control process or during a normal maintenance outage.
State of the art emergency shutdown systems, which are known also as Safety Instrumented Systems (SIS), can control shutdown valves, which are known as critical valves, such as emergency shutdown valves. These Safety Instrumented Systems (SIS) have a number of features to detect plant failures or individual process failures and generally include redundancies in performance of the safety system for added reliability. However, such existing safety systems have not typically provided for the preventative testing of the shutdown valves, other than by undertaking the full stroking of the critical valve at some random time period. In practicing the existing safety systems, a full stroking or a completely closing of the shutdown valves can cause an undesirable disruption in the plant processes.
A need exists for systems and methods for providing testing of shutdown valves, such as emergency valves, without undertaking full stroking of the valve or requiring the complete stopping of total operations of the plant and/or safety system.
A need exists for simple, secure, and reliable systems for testing critical valves without completely stopping the production processes of a facility, including plants, refineries, power industry operations, and combinations thereof.
The embodiments meet these needs.
The embodiments are detailed below with reference to the listed figures.